This invention pertains to drawers which are made from plastic in a single piece by injection molding and more particularly to such drawers having double walled sides with the space between the double walls of the sides being accessible from the bottom and stiffened with transverse ribs. The drawer is furthermore provided at its lower end with an insertion ledge which has on its bottom the guidepath for rollers, and the front of the drawer is provided with attachments for the application of a front facing.
Single piece drawers have proven very suitable in various respects. They are already complete upon manufacture and require no further assembling. They have proven very suitable in particular for kitchens, for articles or furniture used in the medical field etc., since they are easy to keep clean, and, in view of their method of manufacture, have rounded corners and edges in which dirt cannot accumulate.
Previously known drawers of this type, however, have several disadvantages. Since for various reasons, and particularly reasons of manufacture, these drawers must have uniformly thick walls, and the wall thicknesses must furthermore not be too great, the result is, even with a design which takes these facts into consideration, that, for instance, the resistance to warping and in general the dimensional stability are not sufficient and leave something to be desired. Drawers are heretofore known in which the guides have been developed separately and, in particular, also stiffened with transverse ribs. Of course, doubling has been effected for purposes of stiffening, particularly that of the side walls, by extending them from their top edge downward, approximately in the form of a skirt. In addition stiffening ribs have also already been developed in the space produced thereby. Other drawer constructions are known in which the space between the double walls of the side are covered off towards the bottom. This covering was effected also in the case of known drawers by means of a separately applied guide ledge, for instance with the part of the drawer guide which is to be fastened to the drawer with the opposite part thereof attached firmly to the body of the piece of furniture.
For molding reasons, freedom in design is limited in the case of single piece drawers. The doubling of the side walls and the provision of ribs and the like itself requires relatively expensive molds. Such molding is limited not only because multi part molds are difficult to manufacture and to control but also because, for instance, it is impossible in all cases to produce undercuts.
Another disadvantage of known constructions of single piece plastic drawers is that they excessively vibrate in response to mechanical blows because the large width bottom of the drawer acts to a certain extent as a membrane. Even if the side walls are strengthened to a certain extent by doubling and even if ribs are arranged between them, experience shows that it is not possible to avoid the "ringing" of such drawers.
In the case of single piece plastic drawers it is furthermore difficult to produce a sufficiently firm invisible attachment of the drawer to the front plate to which the handle is fixed. The customary connection of the drawer body by means of dowel pins molded thereon which are then fastened in corresponding dowel holes in the front facing has not always proved to stand up properly in use. Therefore, further types of attachments have also been used, for instance screws, which were fed from the inside through an end wall of the drawer into the front plate. These attachments are visible and thus are not only aeshetically disturbing but also the screw heads which lie against the front inner wall of the drawer easily become dirty and are difficult to keep clean. In drawers with so called full extension or double extension, it is know to extend the lateral guide ledges beyond the rear wall of the drawer somewhat, or lengthen their support, so that even when the drawer is pulled out fully and the rear wall of the drawer lies, for instance, in the same plane as the rest of the front wall of the article of furniture, the drawer is still reliably held. In this connection, however, the disadvantage has been noted in known drawer constructions that with the needed lengthened drawer guides it is not possible to avoid, both in the inserted condition of the drawer and in its fully extended position, a lateral movement or "flapping" of the drawer due to the play between the two parts of the opposed drawer guides.